Mass spectrometric studies. IX. Benzylidenemalonic esters and related compounds

1971 ◽  
Vol 24 (4) ◽  
pp. 823 ◽  
Author(s):  
QN Porter ◽  
CR Ramsay
Keyword(s):  
Mass Spectra ◽  
Alkoxy Group ◽  
Mass Spectrometric ◽  
Neutral Fragment ◽  
Carbonium Ion ◽  
Skeletal Rearrangements ◽  
Related Compounds

Skeletal rearrangements resulting from alkoxy-group migrations are prominent in the mass spectra of some benzylidenemalonic esters, and involve elimination of C3O2 as a neutral fragment. Similar rearrangements of a chloride atom dominate the mass spectra of benzylidenemalonyl chloride, but migrations of alkyl and aryl groups are unimportant in the mass spectra of structurally related benzylidene β-diketones. The rearrangements observed have been rationalized as the result of a four-centre migration to a carbonium ion centre.

Mass Spectrometric Studies. XIII. Spirocyclic Glycidic Esters

1979 ◽  
Vol 32 (9) ◽  
pp. 1983 ◽  
Author(s):  
J Baldas ◽  
D Iakovidis ◽  
QN Porter
Keyword(s):  
Mass Spectra ◽  
Alkoxy Group ◽  
Mass Spectrometric ◽  
Deuterium Labelling ◽  
Ring Contraction ◽  
Ring Junction

The mass spectra of a series of spirocyclic glycidic esters derived from cyclo-butanones, -pentanones, -hexanones, -heptanones and -octanones show the following characteristic fragmentations: (i) a rearrangement involving migration of the ester alkoxy group to the ring junction, followed by elision of the group COCR=O (R = H or Me), and (ii) loss of the alkoxycarbonyl group by α-fission, followed by ring-contraction and loss of the elements of acetaldehyde. The major fragmentations are supported by deuterium-labelling experiments, and a number of minor decompositions are described.

Proton magnetic resonance and mass spectrometric studies on derivatives of sodium 2-O-α-D-mannopyranosyl-D-glycerate and related compounds

1969 ◽  
Vol 47 (21) ◽  
pp. 4083-4086 ◽  
Author(s):  
J. N. C. Whyte
Keyword(s):  
Magnetic Resonance ◽  
Methyl Ester ◽  
Proton Magnetic Resonance ◽  
Mass Spectra ◽  
Red Alga ◽  
Mass Spectrometric ◽  
Derivatives Of ◽  
Related Compounds

The proton magnetic resonance (p.m.r.) and mass spectra of the methyl ester pentaacetate of sodium 2-O-α-D-mannopyranosyl-D-glycerate from the red alga Rhodomela larix are compared to those of related compounds to affirm the assigned structure.

Mass spectrometric studies. XI. Skeletal rearrangements in acylhydrazines

1972 ◽  
Vol 25 (3) ◽  
pp. 523 ◽  
Author(s):  
QN Porter ◽  
AE Seif
Keyword(s):  
Nitrogen Atom ◽  
Alkyl Group ◽  
Phenyl Ring ◽  
Mass Spectra ◽  
Mass Spectrometric ◽  
The Other ◽  
Hydrogen Atoms ◽  
Neutral Product ◽  
Skeletal Rearrangements ◽  
Phenyl Compounds

The mass spectra of mono- and di-alkyl-N,N'-dibenzoylhydrazines contain rearrangement ions arising from initial migration of a benzoyl or alkyl group from one nitrogen atom to the other. The spectra also contain ions resulting from N-N fissions accompanied by transfer of one or two hydrogen atoms. The spectra of the mono- and di-phenyl compounds are simpler, but that of the monophenyl compound contains an ion in the formation of which two hydrogen atoms have been transferred to the neutral product from a phenyl ring.

Mass spectrometric studies. V. Benzylidenemalonic acid and related compounds

1969 ◽  
Vol 22 (2) ◽  
pp. 405 ◽  
Author(s):  
J Baldas ◽  
QN Porter ◽  
CCR Ramsay
Keyword(s):  
Oxygen Atom ◽  
Mass Spectra ◽  
Methoxy Group ◽  
Mass Spectrometric ◽  
Atom Transfer ◽  
Oxygen Atom Transfer ◽  
Rearrangement Process ◽  
Related Compounds ◽  
Fragmentation Processes

The mass spectra of benzylidenemalonic acids are dominated by dehydration to species formulated as anhydrides, except in cases where ortho effects alter the fragmentation. Furfurylidenemalonic acid shows a novel rearrangement process involving an oxygen atom transfer. The mass spectra of the corresponding dimethyl and monomethyl esters have also been examined. The former show marked methoxy group migrations, whereas the latter have spectra in which fragmentation processes characteristic of both the parent acids and the diesters are observed.

scholarly journals Isocyanate und verwandte Verbindungen des trimeren Phosphornitriddifluorids / Isocyanates and Related Compounds of Trimeric Phosphor-difluoronitride

1971 ◽  
Vol 26 (7) ◽  
pp. 679-683 ◽  
Author(s):  
Herbert W. Roesky ◽  
Enno Janssen
Keyword(s):  
Ir Spectra ◽  
Elemental Analysis ◽  
Mass Spectra ◽  
H Nmr ◽  
Carbonic Acids ◽  
Related Compounds

P3N3F5NCO was prepared by reaction of P3N3F5NSO with (COCl) 2. Substituted amides were obtained from the reaction of P3N3F5NSO with carbonic acids e. g. P3N3F5NHCOCH3, P3N3F5NHCOC2H5, and P3N3F5NHCOC3H7. If these substances were treated with PCl5 the following compounds P3N3F5N = CClCH3, P3N3F5N = CClCH5, and P3N3F5TN = CClC3H7 were formed. They reacted with nucleophiles to give P3N3F5N = CNH2CH3, P3N3F5N = TN (CH3) 2C2H5, and P3N3F5N = CN (CH3) 2CH7. The properties of these compounds are described. They were characterized by elemental analysis and IR-spectra. 19F-, 1H-NMR, and mass spectra are reported.

Mass spectra of bithiophthalide and related compounds

1971 ◽  
Vol 8 (2) ◽  
pp. 225-230 ◽  
Author(s):  
Charks W. Koch ◽  
I. Hodge Markgraf
Keyword(s):  
Mass Spectra ◽  
Related Compounds

scholarly journals The Mass Spectra of Sepiomelanin and Related Compounds

1968 ◽  
Vol 89 (6) ◽  
pp. 594-596 ◽  
Author(s):  
Yoshimori OMOTE ◽  
Hiroko YASUDA ◽  
Yoshimori FUJINUMA ◽  
Noboru SUGIYAMA
Keyword(s):  
Mass Spectra ◽  
Related Compounds

Nucleic Acid Related Compounds. 5. The Transformation of Formycin and Tubercidin into 2′- and 3′-Deoxynucleosides

1973 ◽  
Vol 51 (9) ◽  
pp. 1313-1321 ◽  
Author(s):  
Morris J. Robins ◽  
James R. McCarthy Jr. ◽  
Roger A. Jones ◽  
Rudolf Mengel
Keyword(s):  
Nucleic Acid ◽  
Mass Spectra ◽  
Sodium Iodide ◽  
Excess Sodium ◽  
Related Compounds

Reaction of tubercidin (4-amino-7-β-D-ribofuranosylpyrrolo[2,3-d]pyrimidine) (1) with α-acetoxyisobutyryl chloride in the presence of excess sodium iodide in acetonitrile gave an acylated iodo intermediate (2) which was converted into 3′-deoxytubercidin (4) by hydrogenolysis and subsequent saponification.Analogous treatment of formycin (7-amino-3-β-D-ribofuranosylpyrazolo[4,3-d]pyrimidine) (5) gave 3′-deoxyformycin (6) and 2′-deoxyformycin (7) in an approximate ratio of 3:2. These purified nucleosides, 6 and 7 were individually deaminated enzymatically to give 3′-deoxyformycin B (8) and 2′-deoxyformycin B(9).Biological rationale, n.m.r., and mass spectra of these antibiotic-derived deoxynucleosides are discussed.

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